We have an orchestrator which gets called by timer trigger every minute. In the orchestrator, there are multiple activity triggers called in function chaining mechanism. However there was one instance, where the each activity trigger was called twice with a time difference of just 7 milliseconds. What I am assuming is when the 1st activity trigger was called, the checkpoint was delayed, even though the process had done its job, so when the orchestrator restarted, it executed the 1st activity trigger again as it did not find data in azure storage queue. Can somebody confirm if this would be the case or is there some issue with the way activity trigger behave?
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Divya Poojari
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Any update now? If it helps you, please accept it as answer.(click on the check mark beside the answer to toggle it from greyed out to filled in.) – Joey Cai Oct 25 '19 at 02:27
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This is the replay behavior of the orchestrator that you are observing. If an orchestrator function emits log messages, the replay behavior may cause duplicate log messages to be emitted. This is normal and by-design. Take a look at this documentation for more information.
When an orchestration function is given more work to do, the orchestrator wakes up and re-executes the entire function from the start to rebuild the local state. During the replay, if the code tries to call a function (or do any other async work), the Durable Task Framework consults the execution history of the current orchestration. If it finds that the activity function has already executed and yielded a result, it replays that function's result and the orchestrator code continues to run. Replay continues until the function code is finished or until it has scheduled new async work.
Joey Cai
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